RAM 2500 Van V8-318 5.2L VIN T Magnum CNG SFI (1997)
Overdrive Switch: Testing and Inspection
The overdrive off switch, valve body solenoid, case connectors and related wiring can all be tested with a 12 volt test lamp or a volt/ohmmeter. Check
continuity of each component when diagnosis indicates this is necessary.
Switch and solenoid continuity should be checked whenever the transmission fails to shift into fourth gear range.